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Biomedical subjects

H Koçak

Publications and source records attributed to H Koçak.

At least 37 records · Page 2Linked to original sources
PubMed1999

Fine needle aspiration biopsy (FNAB) in fibrous and non-fibrous soft oral tissue lesions.

The use of fine needle aspiration biopsy (FNAB) in the diagnosis of many lesions in different parts of the body is quite widespread, while it has been used for oral lesions only very recently. This technique has many advantages including ease of use, cost effectiveness, convenience and accuracy. The present study, investigated the diagnostic value of FNAB in solid oral lesions using, specimens from 90 patients (56 females, 34 males), with ages ranging from 7-70 years which were examined in comparison with their histopathological sections. Cytological specimens were evaluated based on the presence of diagnostic cells. Ninety cases were divided into two major groups those with fibrous and nonfibrous lesions, for the the purposes of histopathological diagnosis. Among all fibrous lesions, cytological diagnosis was possible in 20 cases, whereas 45 out of 49 non-fibrous oral lesions yielded diagnostic cells. In conclusion it was shown that FNAB was not very diagnostic in fibrous lesions. However, in lesions with loose stroma, rich in vessels or inflammatory cells, and in malignant tumors, FNAB was a very successful method which yielded a correct diagnosis.

Adolescent↗
PubMed1997

Cardiac involvement in childhood polyarteritis nodosa.

In this report, we evaluated the cardiac findings of 15 children with polyarteritis nodosa. The age range of the patients was 4-14 years; with a mean of 10 years. All have had systemic involvement of the disease. The most common findings in cardiac evaluation were diminished left ventricular systolic functions and mild mitral and/or tricuspid valve regurgitation. One patient had pericardial thickening with no effusion. One had sinus tachycardia. There were no signs of myocardial infarction or ischemia clinically or electro-cardiographically. In conclusion, we did not find cardiac complications, such as pericarditis or myocardial infarction, to be as frequent as in previous reports. However, even in asymptomatic patients, systolic dysfunction or valvular involvement were common findings in patients with polyarteritis nodosa, which were not reported previously. These findings may be due to the histological changes of the myocardium or atrioventricular valves. Although these were not severe and fatal lesions, long-term follow-up of these patients with echocardiography may help to determine the course of cardiac involvement.

Adolescent↗
PubMed1997

Brain cortex Na(+)-K+ ATPase activities in streptozotocin-diabetic and pentylenetetrazol-epileptic rats.

The aim of this study was to investigate the brain cortex Na(+)-K+ ATPase activity in rats made diabetic by streptozotocin and epileptic by pentylenetetrazol. Streptozotocin diabetic rats showed a significant decrease in brain cortex Na(+)-K+ ATPase activity whereas the pentylenetetrazol treatment caused no significant change in enzyme activity. On the other hand, no brain cortex Na(+)-K+ ATPase activity could be detected in all the diabetic rats treated with pentylenetetrazol. Our results concluded that reduced Na(+)-K+ ATPase activity in streptozotocin diabetic rats may contribute to the pathogenesis of metabolic complications of the central nervous system, and that the undetectable enzyme activity in diabetic convulsing rats may result from considerable damage or necrosis of brain tissue during pentylenetetrazol seizures.

Animals↗
PubMed1996

The coexistence of familial Mediterranean fever and polyarteritis nodosa; report of a case.

We describe a 14-year-old boy with a 5-year history of familial Mediterranean fever (FMF), treated with colchicine, who developed polyarteritis nodosa (PAN). He was admitted to our hospital with fever, general weakness, arthritis, and purpura. Five weeks after admission, hypertension was noted. Skin biopsy showed perivascular leukocyte infiltration in the epidermis. An aortography revealed multiple aneurysms of the renal, common hepatic, and intercostal arteries. He was treated with intravenous methylprednisolone, oral cyclophosphamide, and azathioprine. The known rare association of FMF and PAN is discussed.

Adolescent↗
PubMed1996

Bacteriology of dentoalveolar abscesses in patients who have received empirical antibiotic therapy.

We investigated aspirates of pus from dentoalveolar abscesses in 13 patients who had received empirical antibiotic therapy within 1 month before presentation at our facility. The antibiotics administered were lincomycin, amoxicillin, ampicillin, or a cephalosporin. Information on antibiotic therapy was obtained from the patients' medical histories. Cultures of all dentoalveolar abscesses yielded organisms. A total of 70 isolates (42 anaerobes and 28 facultative organisms) were recovered, representing 5.3 isolates (3.2 anaerobes and 2.1 facultative organisms) per specimen. The counts of bacteria ranged from 5 X 10(7) cfu/mL to 8 X 10(11) cfu/mL (mean count, 1.4 X 10(11) cfu/mL; median count, 2.3 X 10(10) cfu/mL). The predominant isolates were Prevotella species (25.7% of isolates), Peptostreptococcus species (17.1%), and Streptococcus species (14.2%). This study illustrates the polymicrobial nature of dentoalveolar abscesses as well as the predominant role played by anaerobic bacteria.

Adolescent↗
PubMed1996

Detection of seizures from small samples using nonlinear dynamic system theory.

The electroencephalogram (EEG), like many other biological phenomena, is quite likely governed by nonlinear dynamics. Certain characteristics of the underlying dynamics have recently been quantified by computing the correlation dimensions (D2) of EEG time series data. In this paper, D2 of the unbiased autocovariance function of the scalp EEG data was used to detect electrographic seizure activity. Digital EEG data were acquired at a sampling rate of 200 Hz per channel and organized in continuous frames (duration 2.56 s, 512 data points). To increase the reliability of D2 computations with short duration data, raw EEG data were initially simplified using unbiased autocovariance analysis to highlight the periodic activity that is present during seizures. The D2 computation was then performed from the unbiased autocovariance function of each channel using the Grassberger-Procaccia method with Theiler's box-assisted correlation algorithm. Even with short duration data, this preprocessing proved to be computationally robust and displayed no significant sensitivity to implementation details such as the choices of embedding dimension and box size. The system successfully identified various types of seizures in clinical studies.

Algorithms↗
PubMed1996

The incidence and significance of increased backscatter in myocardial ultrasonography of patients on hemodialysis.

Ultrasonic backscatter is substantially modified by pathologic changes in myocardium. To define the incidence and significance of increased backscatter in myocardial ultrasonography of patients on chronic hemodialysis, 41 patients (aged 9-63 years) and 20 healthy controls were studied with conventional two-dimensional and M-mode echocardiography and with analysis of integrated backscatter. Increased histogram values were found in all patients especially in those whose two-dimensional echocardiographic examinations revealed mitral annular calcification (n = 3), aortic valve calcification (n = 2) and aortic plus mitral annular calcification (n = 1). It was concluded that ultrasonographic-integrated backscatter may be a useful method for early identification of cardiac calcification in uremic patients.

Adolescent↗
PubMed1996

Acute maxillary sinusitis from a dental implant: an unusual case report.

In this case report, we present an unusual complication of a previously inserted dental implant leading to maxillary sinusitis. The implant was removed and the patient postoperatively prescribed antibiotic medication. At the follow-up examination, healing was observed without any complications.

Acute Disease↗
PubMed1994

Pericardial and pulmonary involvement in rheumatoid arthritis in Turkey.

Pericardial and lung involvement in rheumatoid arthritis (RA), suspected to be less severe in a developing nation (Turkey), have been evaluated. We have studied clinical, echocardiographic and pulmonary findings (radiological and functional) in 93 consecutive Turkish patients with definite/classical RA. Findings were compared with those of a group of patients with osteoarthritis or local rheumatological conditions (n = 60) in a blind protocol. Fifty patients with systemic lupus (SLE) were studied as a high risk control group for pericardial involvement. While pericardial disease was detected in 5.5% (5/90) of RA patients, it was detected in 6.6% (4/60) of the control patients. SLE patients had a 26% (13/50) prevalence. Interstitial lung disease was found in 27.7% of RA patients but it was present in 6.6% (4/60) of the control patients. We observed that a group of patients with RA in Turkey had a low prevalence of pericardial disease. This is further evidence that RA has a mild course in developing countries.

Adult↗
PubMed1993

A case of cardiac hydatid cyst localized in the lungs bilaterally and on anterior wall of right ventricle.

A 23-year-old man had been coughing with hemoptysis, and had received tuberculostatic medication for four months without any benefit. Upon referral, two-dimensional echocardiography showed a cystic mass located in the anterior right-ventricular wall, without any protrusion into the ventricular cavity. CT examination revealed three cysts in the lung fields bilaterally, additionally a multilocular cystic image in the right-ventricular wall was observed. All components of hydatid cysts in the heart and lungs were removed in the same session by median sternotomy. Extracorporeal bypass was used in this operation.

Adult↗
PubMed1993

Regional odontodysplasia.

An unusual case of regional odontodysplasia in an 8-year-old boy is presented. He was referred to our clinic because of failure of tooth eruption on the left side of the maxilla and frequent fever attacks. Treatment consisted of extraction of the affected teeth, and removal of inflamed tissue.

Child↗
PubMed1993

Transhiatal versus transthoracic esophagectomy for esophageal cancer.

We retrospectively analyzed 238 patients with esophageal carcinoma treated between 1983 and 1991; 120 underwent transthoracic esophagectomy, and 118 underwent transhiatal esophagectomy. The two groups were statistically similar in preoperative characteristics, except that upper esophageal cancer was more frequent in the transhiatal esophagectomy group than in the transthoracic esophagectomy group (p < 0.01). The rate of postoperative complications differed significantly in wound infection (21% in patients who underwent transthoracic esophagectomy, 10% in those who underwent transhiatal esophagectomy; p < 0.05) and empyema (11% with transthoracic esophagectomy, 1% with transhiatal esophagectomy; p < 0.01). Pneumothorax was detected in 24% of the transhiatal esophagectomy cases. Intraoperative blood loss was 1340 +/- 490 ml in the transthoracic esophagectomy group and 930 +/- 340 ml in the transhiatal esophagectomy group (p < 0.001). Hospital mortality was 11% in the transthoracic esophagectomy group and 6.7% in the transhiatal esophagectomy group. Late complication rate was lower with transhiatal esophagectomy than with transthoracic esophagectomy (11% and 51%, respectively). There was no significant difference in actuarial survival of patients in both groups. Transhiatal esophagectomy, which can be performed in almost all levels of the esophagus, is the safer of the two operations.

Anastomosis, Surgical↗
PubMed1993

Myocardial functions of children with acute poststreptococcal glomerulonephritis.

Left ventricular function was investigated by two-dimensional and M-mode echocardiography in 35 patients with acute poststreptococcal glomerulonephritis and in 25 healthy controls. Six of these patients were found to have myocardial dysfunction during the acute congestive phase and convalescent phases of APSGN. One of these 6 patients, later, died. No correlations were determined between myocardial dysfunction and hypertension, cardiac failure, pericardial and pleural effusion. As a result, left ventricular function may be impaired in acute congestive phase of APSGN and this may affect the course and prognosis of the disease.

Child↗
PubMed1992

The effect of superoxide dismutase and reduced glutathione on cardiac performance after coronary occlusion and reperfusion--an experimental study in dogs.

To determine the effect of Superoxide Dismutase (SOD) and Reduced Glutathione (GSH) as free-radical scavengers on cardiac performance in the reperfusion period up to 60 minutes after occlusion of the Left Anterior Descending artery (LAD), 16 dogs were selected for study. In the 30th and 60th minutes of LAD occlusion and reperfusion periods Cardiac Output (CO), Heart Rate (HR), Mean Arterial Pressure (MAP), Pulmonary Capillary Wedge Pressure (PCWP), Coronary Perfusion Pressure (CPP), Rate Pressure Product (RPP) and Triple Index (TI) values were determined. Of the 16 dogs, 7 as controls and 7 treated with SOD and GSH could be included in the study, and 2 had to be excluded because of death. In the 30th and 60th minutes of reperfusion period, the treated dogs had higher CO and CPP (p less than 0.05, p less than 0.01 respectively), MAP values were different (p greater than 0.05, p less than 0.05 respectively) from controls, whereas lower HR (p less than 0.05, p greater than 0.05, respectively), RPP and TI values (p less than 0.05) were determined. It was concluded that the combination of SOD and GSH may improve cardiac performance in the reperfusion period.

Animals↗
PubMed1992

Oxygen free radical scavengers and reperfusion injury in dog lung preserved in cold ischemia.

Oxygen-derived free radicals are now considered important contributors to tissue injury associated with ischemia and reperfusion. The purpose of this study was to determine the influence of oxygen free radical scavengers on reperfusion injury. The left lower lobes of 15 canine lungs were isolated, preserved, and then reperfused for 120 minutes. Three groups of lobes were studied: Group 1 (n = 5), without ischemia, group 2 (n = 5) four hours of cold ischemia in Euro-Collins solution, group 3 (n = 5) four hours cold ischemia+oxygen free radical scavenger glutathione (0.1 nmol/L) given at the moment of perfusion. Extravascular lung water (grams per gram of blood-free dry lobe weight) after reperfusion was 2.82 +/- 0.32, 5.06 +/- 0.45, 4.21 +/- 0.33 for groups 1 through 3 respectively (p less than 0.001 group 1 versus group 2, p less than 0.001 group 2 versus group 3). Lung tissue lipid peroxidation, measured as thiobarbituric acid reactive material was 125 +/- 11, 270 +/- 30, and 185 +/- 17 nmol/g dry lobe weight for groups 1, 2 and 3 respectively (p less than 0.05 group 2 versus 1 and group 3 versus group 2). The data suggest that oxygen free radical scavengers attenuate reperfusion injury.

Animals↗